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Gas exchange is the primary role; filtration, digestion, and hormones are not its main tasks.
The trachea is the air-conducting tube; esophagus carries food, bronchioles and alveoli are deeper in the lungs.
The epiglottis covers the airway during swallowing; the glottis is the vocal opening, uvula and pleura have different roles.
Alveoli are the site of diffusion for O2 and CO2; airways conduct air to them.
Boyle’s Law relates volume and pressure in gases; others describe different phenomena.
The diaphragm contracts to enlarge the thoracic cavity; other muscles recruit in effortful breathing.
Oxygenated blood returns to the left atrium; other chambers serve different roles.
Most O2 is bound to hemoglobin; a portion is dissolved in plasma.
Fibrosis stiffens lungs; emphysema increases compliance; asthma/bronchitis affect airways differently.
CO2-driven drive at the medulla governs breathing; hypoxemia also influences breathing via peripheral receptors.
Surfactant lowers surface tension to prevent collapse; it doesn’t seal or fight infection on its own.
Eupnea = normal rate and depth; tachypnea is fast, bradypnea slow, apnea no breathing.
Medulla sets basic rhythm; pons modulates; others have different functions.
CO2 levels strongly influence ventilation; O2 has a lesser role unless hypoxemic.
Residual volume remains after exhalation; other volumes describe active breath components.
Pleura reduce friction and maintain lung position; surfactant is within alveoli.
Tachypnea = rapid breathing; bradypnea slow, apnea absent, hyperpnea deep/rapid during exertion.
The nose is part of the upper airway; others are lower airway structures.
Chemoreceptors sense chemical changes; other receptors respond to pressure, light, or touch.
Dyspnea is subjective work of breathing; others describe absence of breathing or normal work.
Edema thickens membranes hindering diffusion; asthma/bronchitis affect airways, pneumothorax air in pleural space.
Gas exchange occurs across the alveolar-capillary membrane; other surfaces do not directly exchange gases.
Oxyhemoglobin is O2 bound to Hb; carbon dioxide transport has other forms; some O2 is dissolved too.
Nasal mucosa conditions air; epiglottis guards the airway, others serve different roles.
Alveoli reside within the parenchyma; pleura covers the lungs; bronchi/bronchioles are airways.
O2 diffuses into capillary blood; CO2 diffuses from blood to alveoli for expulsion.
COPD involves chronic obstruction; fibrosis thickens tissue; pneumonia is infection; embolism blocks vessels.
Normal adult rate is about 12-20; the other ranges are outside typical resting values.
The phrenic nerve innervates the diaphragm; others have different functions.
Ventilation is the mechanical movement of air; diffusion/perfusion describe gas transfer and blood flow.
Hypoventilation raises CO2, causing acidosis; other options misstate gas changes.
Negative intrapleural pressure keeps lungs expanded; positive pressure would collapse them.
Cough reflex clears secretions; other reflexes protect differently.
Goblet cells produce mucus; mucociliary movement helps clear it, not goblet function alone.
Bronchi branch from the trachea to supply each lung; others are vascular or digestive structures.
Surfactant lowers surface tension; mucus and others have different roles.
Pneumothorax is air in pleural space; others involve fluid or collapsed alveoli differently.
Asthma features airway constriction; dilation is opposite; others are unrelated.
Apnea = no breathing; dyspnea is difficulty, bradypnea slow, hypercapnia high CO2.
Pulmonary function tests assess lung capacity and airflow; others evaluate different systems.
Hyperpnea is increased depth and rate with activity; hyperventilation is excessive ventilation not always with exertion.
Lower lung zones are more perfused when upright due to gravity; upper zones less perfused.
Expiration is mainly passive via elastic recoil; active muscles engage during effortful breathing.
Trachea has cartilage rings; bronchi also have cartilage but progressively less, bronchioles do not.
Pulmonary vasoconstriction reduces perfusion; vasodilation increases it; other options describe gas levels.